Power-operated lock for spring switches



Nov. 6, 1934. J. A. PEABODY POWER OPERATED LOCK FOR SPRING SWITCHESFiled July 2, 1930 INVENTO ATTORNEY Patented Nov. 6, 1934 UNlTED STATESPATENT OFFICE POWER-OPERATED LOOK FOR SPRING SWITCHES Application July2, 1930, Serial No. 465,306

19 Claims.

This invention relates to power-operated locking devices for springswitches.

Track switches, commonly known as spring switches, are held in oneposition, usually the normal position, by a heavy spring, which acts toreturn the switch points automatically to the normal position when theswitch is trailed, a suitable oil dash-pot device being commonlyemployed to retard the return movement of the switch points, so that thepoints are not shifted back and forth by the successive wheels of thetrain trailing the switch. Since the spring or some of the connectionsto the switch points may be broken or otherwise out of order, so thatthe points might be displaced by the wheels of a train passing over theswitch in the facing direction, and thereby cause derailment, it is notconsidered safe for a train to travel over a spring switch in the facingdirection at normal speeds. There are many applications of springswitches, however, where train delays would be avoided if trains couldpass over the spring switch in the facing direction at the normalrunning speeds and not be required to reduce speed.

In accordance with this invention, it is proposed to provide lockingmeans of the plunger type for positively holding the switch points inthe normal position, so that when this locking means is effective,trains may safely pass over the switch in the facing direction at highspeeds.

One object of the present invention is to provide a power-operatedlocking means for holding a spring switch in the normal position, thislocking means being normally ineffective, and also to provide suitablecontrolling means for the locking means, so that the switch isautomatically locked upon approach of trains travelling in the facingdirection, but remains unlocked for a train travelling in the oppositedirection and trailing the switch.

A further object of the invention is to control the signals, governingtraffic in opposite directions over a spring switch, in accordance withthe locked or unlocked condition of the switch, so that the signalgoverning trafiic in the'facing direction over the switch cannot clearunless the switch is locked, and the signal governing traflic in theopposite or trailing direction cannot clear if the switch is locked.

Other objects, characteristic features and advantages of the inventionwill be in part apparent, and in part pointed out, as the descriptionprogresses.

The accompanying drawing illustrates in a simplified and diagrammaticmanner one typical embodiment of the invention applied to a springswitch at one end of a passing siding on a single track railroad,assumed to be equipped with an automatic block signal system, the partsand circuits being shown in this drawing more with the object of makingit easy to understand the nature and principles of the invention, thanfor the purpose of showing specifically the mechanical construction andarrangement of parts and circuits that would be preferably employed inpractice.

Referring to the accompanying drawing, the track switch SW, shownconventionally, is of the usual type and construction. Mechanicallyconnected to the movable points of this switch SW in the usual way is asuitable spring and dashpot mechanism, shown conventionally anddesignated S, which acts in the usual way to move the switch points tothe normal position and hold them in that position. A switch stand orhandthroW mechanism HT of the usual construction is also connected tothe switch points, so that the switch may be shifted manually to thereverse position, to permit trains to enter the siding. This hand-throwdevice HT is preferably connected to the spring mechanism S so that theswitch points may be thrown without acting in opposition to the spring.

The track is divided into track circuit sections 5, 6, '7 and 8 in theusual way, each track section having a track battery and a track relay,these track relays being designated 5T, 6T, etc. The track circuitsection 'lis relatively short as shown, for example, about 800 feetlong; and the track circuit section 8 is the usual detector trackcircuit section at the switch SW. An absolute or stopand-stay signal 2governs train movement from right to left into the stretch of singletrack between the end of the siding shown and the next adjacent siding.The approach permissive signal 1 governs traffic in the facingdirection' over the switch SW; and the signal 3, next in the rear of thesignal 1, governs traffic in the same direction as'signal 1.

These signals 1, 2 and 3, which are illustrated conventionally assemaphore signals, but may be color-light signals or any other suitabletype, are assumed to be controlled in accordance with the circuits andprinciples of the well-known type of block signalling system for singletrack railroads, commonly known as the absolute-permissive-block system.A block signal system of this type is shown and described, for example,in the patent to S. N. Wight, No. 1,294,736, dated February 18, 1919. Inorder to simplify the i1- lustration, no attempt has been made to showall of the circuits for the control of the signals 1, 2 and 3, onlythose circuits more directly related to the invention having beenconventionally illustrated; but reference may be made to the patent toS. N. Wight, above mentioned, for other detailsof the signallingcircuits.

Each of these signals 1, 2 and 3 is controlled by a suitable signal orline relay, usually of the neutral-polar type to provide for threepositions or indications. The line relays 1H and 2H are shown forcontrolling the signals 1 and 2, but

the caution control for these signals is omitted.

The energizing circuits for these relays are more conveniently discussedlater in connection with the explanation of the operation of theinvention.

The locking device or mechanism of this invention, illustratedconventionally and included within the dotted lines WL, comprises a lockrod LR, connected in the usual way to the movable points of the switchSW. A locking bolt or plunger 10 is arranged to enter a hole 11 in thislock rod LR, when the switch SW is in the normal position, and thuspositively lock the switch points. Said lock rod LR and locking plunger10 are suitably supported and guided in a frame or casing partiallyindicated at 12. The locking plunger 10 is connected by'a pivoted link13 to a gear14. Fastened to the shaft 15 (indicated in part by a dashline) to which the gear 14 is fixed, are two circuit controlling earns16 and 17. Projecting insulated lugs on these cams 16 and 17 co-operatewith rollers on spring contact fingers 18, 19, 20 and 21, so as to movethese fingers into and out of engagement with stationary contacts,indicated conventionally as arrows.

The main gear 14 of the locking mechanism WL is driven by a suitableelectric motor M, having an armature 22 and two reversely arranged fieldcoils or windings 23 and 24, through a friction' clutch 25, and suitablereduction gearing, illustrated as one pinion 26. The shaft of the motorM is provided with a socket 27 to receive the end of a hand crank 28, sothat the motor shaft may be turned by hand. Suitable provision is madefor cutting off the'supply of current to the motor M when the hand-crank28 is used. As shown, the hand crank 28 when not in use is assumed tocompl'ete a circuit through contacts 29 included in the motor circuit,so that when the hand crank is removed and inserted in the socket 27,the circuit through the motor armature is broken. Any other suitablemeans,

'7 such as'disclosed, for example, in the patent to W. K. Howe, No.1,466,903, dated Sept. 4, 1923, may be employed for the same purpose.

Considering now the mode of operation of the invention, the parts andcircuits are shown in the usual or normal condition, the locking plunger10 being disengaged from the lock rod LR, and the switch being unlocked.indicates stop, and the signal 3 next in the rear indicates caution. Thesignal 2indicates clear.

Assuming that a train, travelling from left to right in the facingdirection toward the switch SW, enters the stretch of single track atthe left of this switch, then the energizing circuit for the line relay2H is broken, to cause the signal 2 to indicate stop, by the action ofthe tumble-down circuits characteristicof the absolute-permissive-blocksystem, as disclosed more in detail in said patent to S. N. Wight abovementioned. The de-energization of the 'line re- 5 lay 2H closes anenergizing circuit for the motor The signal 1v M of the lockingmechanism so as to lock the switch SW. This circuit may be traced fromindicating a connection to one terminal of the battery or other suitablesource of current, through the front contact 30 of the track relay 7T,wire 31, front contact 32 of track relay 8T, wire 33, back contact 34 ofrelay 2H, wire 35, back contact 36 of a directional stick relay 2S, wire37', contact finger 19, wire 38, motor field winding 23, wire 39,armature 22, wire 40, through crank controlled contacts 29, toindicating a connection to the other terminal of this battery.

When the armature 22 and the field winding 23 of the motor M are thusenergized, the gear 14 is turned from the position shown in a clockwisevdirection, to move the locking plunger 10 into the hole 11 in the lockrod LR, and thus positively lock the switch SW in its normal position.In this locked position of the locking plunger 10, the end of theconnecting link 13 is beyond dead center and adjacent to the fixed stop41, so that the locking plunger 10 cannot be displaced by vibration orthe like from its locking position. I

During this movement of the gear 14, the circuit controller cams 16 and17 are shifted from the positions shown approximately a half revolution,to open the contact fingers 19 and 20, and close the contact fingers 18and 21. The opening of the contact finger 19 breaks the motor energizingcircuit above traced, so that operating current is cut off from themotor at the end of this locking operation.

The closing of the contact finger 21, at the end of this lockingoperation, completes a break in the energizing circuit for the linerelay 1H, so that if traiiic conditions permit, this relay 1H may beenergized over a circuit, which is only partially shown and may betraced from (C), indicating a connection to the usual common returnwire, relay 1H, wire 42, front contact 43, track relay 7T, wire 44,front contact of track relay 8T, wire 46, which preferablyincludes aswitch circuit controller contact WP, closed inthe normal position ofthe switch, contact finger 21, wire 47, and thence through othercontrolling contacts of the signalling system, to a source of currentconnected to the common return wire.

Thus, when a train approaches the switch SW in the facing direction, thelocking mechanism WL is operated to lock the switch, and if this lockingoperation actually occurs, then only may the signal 1 clear.

If the switch SW should not be over in the full normal position, or ifthe locking plunger 10 cannot enter the hole'll in. the lock rod LR forany other reason, the gear 14 can not be moved far enough to close thecontact finger 21, and the signal 1 can not clear. In such a case, thefriction clutch 25 slips; and if desired, suitable timeelement meanssuch as disclosed, for example, in the application of S. N. Wight, Ser.No. 293,664, filed July 18, 1928, may be employed to cut offtheoperating current, after the lapse of a predetermined time, in caseof failure in the locking operation.

jVhen this train in question, assumed to have caused locking of theswitch, has passed beyond the switch SW and out of the detector trackcirof track relay 8T, wire 33, front contact '34'of relay 2H, wire 48,contact finger 18 (now closed) wire 49, motor field 24, and thencethrough the armature 22 to the same as in the locking circuit.

With the motor field 24 energized, the armature 22 of the motor Mrotates in the opposite direction and drives the crank 14counter-clockwise to withdraw the locking plunger 10 to its unlockedposition. This opens the circuit for the line relay 1H, putting thesignal 1 tostop; opens the contact finger 18 to cut off the operatingcurrent to the motor M; and closes the contact finger 20 to complete acircuit for clearing the signal 2, which may be traced from through thefront contact 50 of the relay 2H, signal 2, wire 51, and contact finger20 to In this way, the switch SW is automatically unlocked, afterpassage of the train in the facing direction which caused locking of theswitch.

When a train on the siding trails the switch SW, the switch points maybe freely moved, since the lock plunger 10 is then disengaged. If theswitch SW should be locked for any reason, the signal 2 is held in thestop position, irrespective of the control of its line relay 2H, by theopening of the contact finger 20.

When a train trailing the switch SW enters the track circuit section '7and de-energizes the line relay 21-1, the locking circuit for the motorM is broken at the front contact 30 of the track relay 7T before it isclosed at the back contact 34 of the line relay 2H. Also, thedirectional stick relay 2S is energized over a circuit from through theback contact 30 of the track relay 7T, wire 52, circuit controller 53 ofsignal 2, closed in the clear and caution positions, wires 54 and 55,relay 2S to and when the line relay 2H drops, the stick relay 2S isstuck up through its front contact 56 and a back contact 5''! of therelay 2H. The energization of this stick relay 2S breaks at its backcontact 36 the locking circuit for the motor M, so that after the trainin question, travelling in the trailing direction, passes out of thetrack circuit section '7 and into and through the track circuit sections5 and 6, this locking circuit is maintained open and an idle lockingoperation is avoided.

The directional stick relay 23 is also picked up by a train travellingfrom right to left past the switch SW on the main track; andconsequently the locking mechanism WL is not operated to lock the switchwhen this train advances into the approach locking track circuitsections 5 and 6, as otherwise would occur if'it were not for this stickrelay 2S and its control of the locking circuit. For such a trainmovement in the trail ing direction over the switch SW in its normal ormain track position, it is not necessary to lock the switch points,since the wheels of the train will keep the switch points in the propernormal position, even though the spring and dash-pot mechanism S may notbe fully effective.

From this explanation it can be seen that, for a trailing trainmovement, the signal 2 cannot clear if the locking mechanism WL iseffective to lock the switch SW. In other words, the points of theswitch SW must be free to be moved, if necessary, by the wheels of thetrain trailing the switch, before the signal 2, governing traffic in thedirection of such trailing movement, can clear. This prevents damage orbreaking of the locking device or other parts associated with theswitch, which would otherwise occur, if the wheels of the train wouldforce over the switch points from the locked position.

If the locking mechanism WL, clue to a failure in the operating parts orcircuits, or for any other reason, should not lock or unlock the switchwhen'it should, the hand crank 28 may be used to operate the main gear14 by hand, and move the locking plunger 10 into or out of engagementwith the lock rod LR. For example, if the looking mechanism WL shouldfail to unlock having once been locked by an approaching train, theswitch may be unlocked by hand to permit a train to come off" of thesiding and trail through the switch. Also, when a train approaching theswitch SW in the facing direction automatically locks the switch, asabove explained, it is necessary to use the hand crank to unlock theswitch before the switch stand or handthrow device HT can be operated toreverse the switch and permit this train to enter the siding. When thehand-crank 28 is in use, the circuit through the motor armature 22 isbroken at the contacts 29.

This invention provides for the desirable and requisite safety in theuse of a spring switch and permits train movements at normal speeds inthe facing direction over the switch, thereby facilitating trafiic. Thesignals 1 and 2, governing traffic in opposite directions over thespring switch, are controlled in such a way that these signals may notclear unless it is safe for the train to pass over the switch, that is,is positively locked for train movements in the facing direction andunlocked for train movements in the trailing direction. The switchpoints of the spring switch are positively and securely held by a lockof the plunger type; and since this locking plunger is power-operated,the parts may have the necessary size and strength, and yet the switchmay be automatically locked and unlocked, as required, in spite of thefriction and pressures ordinarily encountered in practice in connectionwith a plunger type lock. Also, provision is made for operating theswitch look by hand, when necessary, either because the lookingmechanism is out of order, or because a train wishes to enter thesiding. Various other characteristic features and advantages of theinvention will be apparent.

The present invention is an improvement upon the disclosure in the priorapplication of Preston and Dicke Ser. No. 187,490 filed April 29, 1927,and no claim is made in this application to any of the subject matterdisclosed in said prior application.

The particular construction and arrangement of parts and circuits shownand described are merely illustrative of one specific embodiment of theinvention, considered diagrammatically, rather than structurally; andvarious additions, modifications and adaptations may be made in thisspecific embodiment without departing from the invention.

What I claim is:-

1. 'In a traffic controlling system for railroads, a track switch,spring means tending to move and hold said switch in the normalposition, a lock rod and locking plunger engageable only in one 146position of the switch for locking said switch, and power-operated meansfor moving said lock plunger to its locked and unlocked positions.

2. In a traffic controlling system for railroads,

a track switch, spring means tending to move and 145 hold said switch inthe normal position, locking means for positively holding said switch inits normal position, power-operated means governed by the approach of atrain for actuating said locking means, and manually operable means for150 Sill GOT

independently actuating; said locking means.

3. In a traffic. controlling system for'railroads, a track switch,spring means tending to move and hold said switch in the normalposition, a plurality of track circuit sections adjacent the switch, anormally energized line relay governed by said track circuits anddeenergized upon occupancy of any of said track circuits by a train,normally in-' active locking means for said switch, and poweroperatedmeans governed by said line relay for rendering said locking meanseffective upon the approach of a train travelling in the facingdirection toward said switch.

4. In a trafiic controlling system for railroads, the combination with aspring switch, a locking plunger for positively holding said switch inits normal position only, an electric motor and gearing for operatingsaid plunger, and manually operable means for also operating saidplunger.

5. In a trailic controlling system of the type described, a springswitch, signals governing traffic in opposite directions over saidswitch, a lock rod connected to the points of said switch, a lockingplunger co-operating with said lock rod to hold said switch points inthe normal position,

power-operated means for positively moving said plunger to and from itslocked position, and circuit controlling means op'eratively connected.to said plunger for selectively controlling said signals.

6. In a traflic controlling system for railroads, a spring switch, aplurality of track circuits adjacent the switch, a line relay governedby said track circuits, a stick relay responsive to the direction oftrain movement over said track circuits, power-operated locking meansfor said switch, and a control circuit for said means including a backcontact of said stick relay and a back contact of said line relay. 7

7. In a system of safety control for spring switches, a plurality oftrack circuits adjacent the spring switch, a line relay governed by saidtrack circuits, a signal governing traffic in the trailing directionover said switch, power-operated'locking means for the switch governedby said line relay, and a clearing circuit for said signal controlled bysaid line relay and by said locking means.

8. In a railway signalling system of the type described, the combinationwith a spring switch, a track circuit adjacent the switch and having atrack relay, a normally disengaged plunger lock for said switch,power-operated means for actuating said lock to its locking position,and a control circuit for supplying power to said means including afront contact of said track relay.

9. ,A locking mechanism of spring switches comprising the lockingplunger, power-operated means having locking and unlocking controlcircuits for actuating said plunger, a plurality of track circuitsadjacent the switch, and a line relay controlled by said circuits foralternatively governing said controlcircuits.

10. Looking means for spring switches, comprising a locking plungeroperable both manually and by power, and signal control circuitsselectively governed in accordance with thelocked or unlocked positionof said plunger.

11. In a traffic controlling system for railroads, a track switch,spring means tending to move and to hold said switch in the normalposition, a signal governing traffic toward said switch in the facingdirection, normally inactive locking means for positively holding saidswitch in its normal position, power-operated means electric motor andgearing for rendering said locking means effective upon the approach ofa train in the facing direction, and means for preventing the clearingof said signal unless said locking means is in its locked condition.

12. In a traffic controlling system for railways, a track switch, asignal governing trafl'ic toward the switch in the facing direction,locking means for positively holding the switch in one extreme position,and reversible motor operated means for rendering the locking meanseffective upon the approach of a train in the facing direction so as toput said signal to stop.

13. In a traflic controlling system for railways, a track switch,locking means for positively holding the switch in one extreme position,and reversible electrically controlled motor operated means forrendering the locking means efiective only upon the approach of a trainin the facing direction.

14. In a railway signal system, in combination, a stretch of track, atrack switch, lock meansfor the switch, power operating means for theswitch lock means, a signal governing traflic over the switch in onedirection, and a translating device controlled by trafiic approachingthe switch from the other direction, for simultaneously operating saidsignal and for making the power operating means effective to control thelock means.

15. In a railway signal system, in combination, a stretch of track, atrack switch, lock means for the switch, power operating means for theswitch lock means, a signal governing trafiic over the switch, in aswitch trailing direction, and a relay controlled by traffic approachingthe switch from the facing point direction, for simultaneously operatingsaid signal to stop and for making the power operating means effectiveto control the lock means to lock the track switch.

16. In .combination, a trailing fiy-back switch, a lock means for theswitch comprising, a looking plunger and lock rod engageable only in thenormal position of said switch, and an electric motor and gearing foroperating said plunger to its locked and unlocked positions.

17. A locking device for trailing fly-back switches comprising, a lockrod connected to the switch points, a locking plunger, the lockrod'being engageable only with said locking plunger and then engageablewith said lock rod only in the normal position of the switch points, anelectric motor and gearing for operating said plunger to the locked andunlocked positions, and circuit controlling means automatically openedand closed in accordance with the position of said plunger.

18. A locking device for trailing fiy-back switches comprising, a lockrod connected to the switch points, only a single locking plungerengageable with said lock rod and then only in one position of theswitch points, an electric motor, and gearing including a frictionclutch for operatively connecting said plunger to said motor.

19. In a traffic controlling system for railways, a trailing fiy-backtrack switch, locking means for positively holding'the switch in oneextreme position, and reversible motor operated means for rendering thelocking means efiective upon the approach of a train in the facingdirection only.

JAMES A. PEABODY.

including an

